1. Technical Field
The present disclosure relates to integrated circuits (IC), and more specifically to scan based testing of an IC containing portions operable in different clock domains when operating in functional mode.
2. Related Art
A scan based test or scan test generally refers to an approach in which storage elements of an integrated circuit (IC) are connected as a scan chain, a scan vector is scanned into the IC through the scan chain, the integrated circuit is placed in an evaluation mode (capture phase) for one or more clock cycles, and the values obtained in the capture cycle are compared with an expected output to determine whether the integrated circuit is operating as desired or not.
On the other hand, functional mode refers to the normal operational mode of an integrated circuit, providing the general utility the circuit is designed for.
An integrated circuit (IC, circuit in general) often contains different portions, which operate based on different clocks. The portions operating based on a single clock are said to operate in corresponding clock domain. Often the phases and/or frequencies of the clock signals are generated without express correlation (i.e., independently or asynchronously).
Scan based testing of such ICs often presents several challenges. Several aspects of the present invention address one or more of such challenges.